Self Retracting Lifelines (SRLs) have been well known in the fall arrest industry. Workers use SRLs as a safety means to arrest a dangerous or potentially life-threatening fall, particularly in high rise construction and maintenance. A worker or other user typically wears a safety harness with an aperture (e.g., a D-ring) that is connected to a hook at one end of the SRL. The other end of the SRL is secured to a permanent structural member of the building or work site. The SRL includes a housing that contains a cable that is wrapped around a central reel body. The cable, being connected to the hook on one end, can “pay out” through an aperture of the housing and retract back on itself through the use of a power spring. SRLs utilize an active braking system positioned within the housing that can quickly stop the cable from paying out when a particular velocity or G-force is detected. Most SRL braking systems have incorporated some form of ratchet/pawl mechanism in which a pawl engages a tooth of a ratchet when the braking system senses sufficient G force or revolutions denoting quick cable pay out. A typical ratchet/pawl braking system is illustrated in U.S. Pat. No. 4,589,523 to Olson et al.
Fall arrest equipment is inherently “active,” meaning that it stops a user in the act of a fall. Fall restraint is “passive,” such as a rope or barrier to keep a user from falling in the first place. OSHA mandates fall protection for workers in such applications where the work surface is over 6 feet off the ground. This can include either type of system. However, most high rise applications use fall arrest equipment and, particularly, SRLs.
Most SRLs are of industry standard sizes, e.g., 65′, 50′, or shorter. Because of the predefined length of the cable, various sized products must be used in accordance with the particular work environment and the distance a worker needs to complete a task. For example, a 65′ retractable may not be used on a job site in which the safe fall range exceeds that distance. However, it is expensive and not always practical to have varying size SRLs on each job site or in storage for use in large contractor warehouses.
Further, there is no known attempt at creating an active SRL that can be adapted for variable fall restraint (passive) protection. With little doubt, it is much safer for a user to avoid falling altogether—even if the worker falls with appropriate fall arrest equipment. This is because a falling worker with active fall restraint equipment will stop with a sudden jerk and the fall and sudden stop can cause panic, discomfort, and possible injury. However, OSHA guidelines will not allow a purely passive restraint system to be utilized where active fall arrest is required. There is no known commercial solution to combine an active fall arrest SRL with a passive restraint feature into one device in which the cable payout distance cannot physically go past a particular job-site requirement (e.g., the falling point off a ledge or roof edge of a building), as well as the possibility of using a single SRL (e.g., 65′ SRL) in a multitude of work environments.